US forces yesterday conducted an airstrike in Raqqa, Syria, targeting Mohamed Emwazi, also known as "Jihadi John," according to a statement issued by Pentagon Press Secretary Peter Cook.

"Emwazi, a British citizen, participated in the videos showing the murders of US journalists Steven Sotloff and James Foley, US aid worker Abdul-Rahman Kassig, British aid workers David Haines and Alan Henning, Japanese journalist Kenji Goto, and a number of other hostages," Cook said in the statement.

"We are assessing the results of tonight's operation and will provide additional information as and where appropriate," Cook added.

US officials are fairly certain Emwazi is dead. The Islamic State has not released an official statement announcing his death.

On November 13th, the US targeted an Iraqi jihadist known as Abu Nabil. The military said this was "the first US strike against an ISIL [Islamic State] leader in Libya" and the "operation was authorized and initiated prior to the terrorist attack in Paris," which was carried out by the Islamic State. From the press release:

On November 13, the US military conducted an airstrike in Libya against Abu Nabil, aka Wissam Najm Abd Zayd al Zubaydi, an Iraqi national who was a longtime al Qaeda operative and the senior ISIL leader in Libya.

Reporting suggests he may also have been the spokesman in the February 2015 Coptic Christian execution video. Nabil's death will degrade ISIL's ability to meet the group's objectives in Libya, including recruiting new ISIL members, establishing bases in Libya, and planning external attacks on the United States.

The press release noted that the strike against Abu Babil "demonstrates [that] we will go after ISIL leaders wherever they operate."

Attacks across the greater Middle East attributed to ISIS as of mid-2015. Reuters The strikes that targeted Emwazi and Abu Nabil should serve as a reminder that 14 years after the September 11, 2001 attacks on the US, the military and intelligence establishment remain hyper-focused on targeting individuals in the hopes of causing the collapse of jihadist groups.

Unfortunately as the US drone campaigns in Pakistan and Yemen have shown, jihadist groups (in those cases, al Qaeda, and al Qaeda in the Arabian Peninsula, respectively) have proven to be resilient in the face of the targeting and killing of its leaders and key operatives. Al Qaeda and its splinter group the Islamic State control territory and have a deep bench of leaders and operatives who are willing to step in for those killed in the air campaigns.

A candle is placed during a vigil in Place de la Republique following the series of deadly attacks in Paris, November 15, 2015.REUTERS/Benoit TessierThe suicide assault in Paris, France should serve as a reminder that these groups cannot be dismantled by air power alone.

Bill Roggio is a Senior Fellow at the Foundation for Defense of Democracies and the Editor of The Long War Journal.